Conduct hematology support care and perform the following tasks: Conduct a variety of leukoagglutination assays of prospective human recipient sera against prospective donor peripheral leukocytes; Conduct microlymphocytotoxicity assays on serum samples from patients; Ascertain the granulocyte phenotype of patients and prospective donors, employing reference granulocyte typing sera in a modified microlymphocytotoxicity toxicity type of procedure; Conduct microgranulocyte cytotoxicity screening assays and absorption studies on serum samples from patients; and Maintain a systematic frozen repository of all serum and/or plasma samples obtained from patients, relatives, and normal donors under study in this program.